Hemophagocytic lymphohistiocytosis (HLH) is an acute and rapidly progressive systemic inflammatory disorder characterized by cytopenia, hyperferritinemia, multiorgan involvement, and hemophagocytosis. The other names for HLH are hemophagocytic syndrome and macrophage activation syndrome. Coronavirus disease 2019 (COVID-19) is associated with cytokine storm and secondary HLH; both are a spectrum of dysregulated immune responses requiring immunomodulatory drugs. Early diagnosis and treatment are a must, as the mortality rate of HLH is 40%. Severe COVID-19 patients should be screened for hyperinflammation using standard laboratory tests and H-score to rule out secondary HLH.
Highlight: This case report highlights the importance of a high index of suspicion of secondary HLH in clinician's minds, which can lead to early diagnosis, prompt treatment, and a good prognosis.
Ramos-Casals M, Brito-Zeron P, Lopez-Guillermo A, et al. Adult haemophagocytic syndrome. Lancet 2014;383(9927):1503–1516. DOI: 10.1016/S0140-6736(13)61048-X
Carvelli J, Piperoglou C, Farnarier CC, et al. Functional and genetic testing in adults with HLH do not reveal a cytotoxicity defect but rather an inflammatory profile. Blood 2020;136(5):542–552. DOI: 10.1182/blood.2019003664
Rivellese F, Prediletto E. ACE2 at the Centre of COVID-19 from pauci symptomatic infections to severe pneumonia. Autoimmun Rev 2020;19(6):102536. DOI: 10.1016/j.autrev.2020.102536
Knaak C, Nyvlt P, Schuster FS, et al. Hemophagocytic lymphohistiocytosis in critically ill patients: diagnostic reliability of HLH-2004 criteria and HScore. Crit Care 2020;24(1):244. DOI: 10.1186/s13054-020-02941-3
Allen CE, Yu X, Kozinetz CA, et al. Highly elevated ferritin levels and the diagnosis of hemophagocytic lymphohistiocytosis. Pediatr Blood Cancer 2008;50(6):1227–1235. DOI: 10.1002/pbc.21423
Lin TF, Ferlic-Stark LL, Allen CE, et al. Rate of decline of ferritin in patients with hemophagocytic lymphohistiocytosis as a prognostic variable for mortality. Pediatr Blood Cancer 2011;56(1):154–155. DOI: 10.1002/pbc.22774
Hayden A, Lin M, Park S, et al. Soluble interleukin-2 receptor is a sensitive diagnostic test in adult HLH. Blood Adv 2017;1(26):2529–2534. DOI: 10.1182/bloodadvances.2017012310
Fardet L, Galicier L, Lambotte O, et al. Development and validation of the HScore, a score for the diagnosis of reactive hemophagocytic syndrome. Arthritis Rheumatol 2014;66(9):2613–2620. DOI: 10.1002/art.38690
Opoka-Winiarska V, Grywalska E, Roliński J. Could hemophagocytic lymphohistiocytosis be the core issue of severe COVID-19 cases?. BMC Med 2020;18(1):214. DOI: 10.1186/s12916-020-01682-y
